1. Field of the Invention
The present invention relates to an endoscope apparatus of an endoscope cover type which uses an endoscope cover to prevent the endoscope from being contaminated and, more particularly, to prevent the contamination of the structure of an insertion tube inserted into an object position to be examined and of the portion adjacent to the object position.
2. Description of the Related Art
Recently, endoscopes have been widely used in the field of medical treatment. When an endoscope used in the field of medical treatment is inserted into a living body, an observation window provided at the tip of an insertion tube is sometimes soiled by bodily fluid, so that it becomes difficult for the endoscope to observe the inside of the living body. Therefore, an endoscope is provided with an air supplying channel or water supplying channel so as to be able to remove the bodily fluid adhered to the observation window by spraying the observation window with fluid, such as washing water and washing gas, which is operated from the proximal end portion of the endoscope. Further, an endoscope is provided with a sucking channel so as to be able to discharge unnecessary bodily fluid. Also, another endoscope is provided with a forceps channel (treatment tool channel) so as to be able to gather tissues by means of biopsy forceps or to be able to give treatment using treatment tools.
For an endoscope examination, a clean endoscope which is sufficiently washed and disinfected before the examination should be used. Thus, when the endoscope provided with a channel such as a supplying gas channel or forceps channel is applied to a patient, the endoscope is washed or disinfected in order to prevent infection. However, it requires a lot of time to wash and disinfect an endoscope completely, which reduces the efficiency of the endoscope.
Therefore, an endoscope apparatus of an endoscope cover type has been considered. In the endoscope apparatus, an endoscope itself is covered with an endoscope cover to be used. Then, the cover is used once and thrown away after used, and then, exchanged. The endoscope itself is kept clean after use and does not require washing and disinfecting.
As an endoscope apparatus of an endoscope cover type for example, U.S. Pat. Nos. 4,646,722 and 3,162,190 disclose an apparatus in which an endoscope insertion tube is inserted into a cover and the insertion tube is covered with the cover to be insulated from surroundings.
A forceps channel and supplying gas and water channels provided in the endoscope heretofore in use might be soiled by bodily fluid and these channels are long and narrow, so that it requires a lot of time to wash and disinfect these channels. Thus, the endoscope cover is provided with a forceps channel and gas and water supplying channels to prevent the endoscope body inserted into the channels from becoming unclean.
In such an endoscope of an endoscope cover type, the insertion tube is washed or disinfected before the tube is inserted. Then, while the insertion tube is kept being covered with an endoscope cover, the tube is inserted into a body cavity of a patient to examine the body cavity and give treatment to the patient. After use, the endoscope cover is removed and thrown away. In this way, an endoscope cover is used only once for a patient and thrown away, therefore, the endoscope is not required to be washed and disinfected, so that the endoscope can be kept clean and is very easily used. Thus, without being washed or disinfected, the endoscope can be continuously used.
However, in the endoscope apparatus of the aforesaid endoscope cover type, no proposal about the construction material which affects the characteristic of an insertion tube, such as flexibility, elasticity and stability, has been supplied. Therefore, in a case in which the endoscope apparatus of an endoscope cover type was inserted deeply inside the object to be examined, the proximal end portion of the insertion tube was bent when the insertion tube was inserted into the body cavity, so that it happened sometimes that the tube could not be easily inserted into it. In a case in which the tube was inserted into the intestines, there was a problem of a difficult inserting operation because the tip of the insertion tube could not be bent along the intestines producing pain in the patient.
If the aforesaid insertion tube was bent to an extreme degree when inserted into an object to be examined, there was danger in which the proximal end operating portion of the insertion tube of the endoscope was bent and deformed in the horizontal direction. In this way, there were cases in which inconvenience was brought about at the time of insertion.
When a clean cover portion is carried, if the form is such that the cover portion of the endoscope insertion tube is coiled and wrapped and put in a wrapping member, a channel such as a forceps channel provided in the endoscope cover becomes a bent shape. Therefore, the cover portion of the endoscope insertion tube containing the aforesaid channel becomes a bent shape. In addition, the insertion tube becomes a bent shape even in a state in which the insertion tube of an endoscope to be covered is covered with the cover portion of the endoscope insertion tube, so that the insertability of the tube into the body cavity will be quite worse. If the cover portion becomes a bent shape, there is inconvenience in which the cover portion is hard to cover the insertion tube of the endoscope to be covered.